MS-CHAP is used for initial authentication.

• A. initial
• B. message-by-message
• C. Both A and B
• D. Neither A nor B

Answer: (A)

MS-CHAP is a challenge-response authentication mechanism used when a remote-access session is being established. The server issues a challenge, the client responds with a value derived from the user’s password, and the server verifies that response to authenticate the user at the start of the connection. It doesn’t authenticate each individual message in the session; after successful authentication, the session can be protected with encryption, but MS-CHAP’s role is the initial verification, not ongoing per-message authentication.